| Electronics > Beginners |
| Why 2 transformers? (pic) |
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| wraper:
Transformers are unlikely to be faulty. And even if transformer is faulty, most likely is was damaged due other components failing. If windings have low resistance, they should be fine. |
| wraper:
--- Quote from: TrickyNekro on January 14, 2019, 02:45:13 am ---The whole supply doesn´t seem to be mains isolated, just keep that in mind, might give you a tingle :-/O edit: under fault conditions most probably though... --- Quote from: wraper on January 14, 2019, 02:34:36 am --- --- Quote from: ataradov on January 14, 2019, 02:16:03 am ---IC1 takes feedback voltage from the unregulated output through D5 and adjusts switching frequency accordingly. --- End quote --- No it does not. TL494 or it's clone is powered though D5. Feedback is taken from resistive divider connected to the output. --- Quote ---adjusts switching frequency accordingly. --- End quote --- PWM duty cycle, not frequency. --- End quote --- Could be both, there are high efficiency supplies that do both. --- End quote --- Can not. It's TL494. In any case, changing switching frequency by itself barely changes output voltage. |
| ataradov:
It is isolated. And I did misspeak, it is obviously changing the duty cycle. |
| wraper:
--- Quote from: ataradov on January 14, 2019, 02:50:11 am ---It is isolated. --- End quote --- I'm not sure what you mean by that. TL494 is powered from secondary side through D5. Pin 12 is Vcc. |
| ataradov:
--- Quote from: wraper on January 14, 2019, 02:58:33 am ---I'm not sure what you mean by that. TL494 is powered from secondary side through D5. Pin 12 is Vcc. --- End quote --- That's a comment about TrickyNekro's comment that this power supply is not mains-isolated. |
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